Cyber Resilience

CVE-2026-42088

Openc3 Cosmos ≤ 7.0.0

Public PoC
Published
04 May 2026
Modified
17 June 2026
Patch / advisory
CVSS Score v3.1 9.6
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N
EPSS Score 0.0034 27th percentile
Risk Priority 65 floored blend · peak EPSS

Summary

CVE-2026-42088 is a critical-severity Execution with Unnecessary Privileges (CWE-250) vulnerability in Openc3 Cosmos. Its CVSS base score is 9.6 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 27th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to AC-6 (Least Privilege) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-42088 is a high-severity vulnerability (CVSS 9.6, AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N) affecting OpenC3 COSMOS prior to version 7.0.0-rc3. The issue resides in the Script Runner widget within the openc3-COSMOS-script-runner-api Docker container, which enables users to execute Python and Ruby scripts. Due to all Docker containers sharing a network, these scripts can bypass API permissions checks, allowing unauthorized access to other services.

Any authenticated user with permission to create and run scripts can exploit this vulnerability remotely over the network. Successful exploitation grants administrative capabilities normally restricted to the Admin Console, including reading and modifying data in the Redis database to access secrets and alter COSMOS settings, as well as reading and writing to the buckets service containing configuration, log, and plugin files.

The vulnerability has been addressed in OpenC3 COSMOS version 7.0.0-rc3, as detailed in the project's release notes and GitHub Security Advisory GHSA-2wvh-87g2-89hr. Security practitioners should upgrade to the patched version to mitigate the risk, associated with CWE-250 (Execution with Unnecessary Privileges).

EU & UK References

Vulnerability Data

OpenC3 COSMOS provides the functionality needed to send commands to and receive data from one or more embedded systems. Prior to version 7.0.0-rc3, the Script Runner widget allows users to execute Python and Ruby scripts directly from the openc3-COSMOS-script-runner-api container.…

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Because all the docker containers share a network, users can execute specially crafted scripts to bypass the API permissions check and perform administrative actions, including reading and modifying data inside the Redis database, which can be used to read secrets and change COSMOS settings, as well as read and write to the buckets service, which holds configuration, log, and plugin files. These actions are normally only available from the Admin Console or with administrative privileges. Any user with permission to create and run scripts can connect to any service in the docker network. This issue has been patched in version 7.0.0-rc3.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1055 Process Injection Stealth
Adversaries may inject code into processes in order to evade process-based defenses as well as possibly elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-28384Same product: Openc3 Cosmos
CVE-2024-46977Same product: Openc3 Cosmos
CVE-2025-28382Same product: Openc3 Cosmos
CVE-2026-42087Same product: Openc3 Cosmos
CVE-2026-42085Same product: Openc3 Cosmos
CVE-2025-28386Same product: Openc3 Cosmos
CVE-2024-43795Same product: Openc3 Cosmos
CVE-2025-28380Same product: Openc3 Cosmos
CVE-2026-42086Same product: Openc3 Cosmos
CVE-2025-28388Same product: Openc3 Cosmos

Affected Assets

openc3
cosmos
7.0.0 · ≤ 7.0.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 6 hardening rules · 6 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V10.2.3
  • V13.2.2

Mitigating Controls (NIST 800-53 r5) AI

Least privilege directly requires that only the minimum necessary authorizations are granted, structurally eliminating execution with unnecessary privileges.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-05 mostly match
prevents

PR.AA-05 directly enforces least privilege so largely eliminates CWE-250 at design time, yet the weakness can still arise from runtime escalation paths, third-party code, or misapplied role definitions outside this single control.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Requiring explicit justification and time-limited grants discourages the routine allocation of unnecessary privileges that would otherwise allow execution with more rights than required.

prevents

Restricting privileged utilities to the fewest trusted users and requiring explicit authorization directly stops developers or operators from embedding or invoking code that runs with unnecessary elevated rights.

prevents

Mandating separate non-privileged identities for routine work and restricting privileged accounts to administrative tasks reduces the chance that everyday operations run with unnecessary elevated rights.

prevents

The control explicitly calls for minimizing privileged identities and disabling unnecessary accounts, thereby reducing the number of processes that run with unnecessary privileges.

prevents

The requirement to restrict privileged access and apply segregation of duties limits the number of processes or accounts that must run with elevated rights, lowering the impact of unnecessary privilege assignments.

mitigates

Forcing distinct roles for initiating versus executing changes reduces the chance that an individual will run with unnecessary privileges to perform both steps.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Windows 10 (1 rule)
  • V-220712 Only accounts responsible for the administration of a system must have Administrator rights on the system. prevents CWE-250
Windows 11 (1 rule)
  • V-253269 Only accounts responsible for the administration of a system must have Administrator rights on the system. prevents CWE-250
Windows Server 2016 (1 rule)
  • V-225007 Only administrators responsible for the member server or standalone or nondomain-joined system must have Administrator rights on the system. prevents CWE-250
Windows Server 2019 (1 rule)
  • V-205746 Windows Server 2019 must only allow Administrators responsible for the member server or standalone or nondomain-joined system to have Administrator rights on the system. prevents CWE-250
Windows Server 2022 (1 rule)
  • V-254428 Windows Server 2022 must only allow administrators responsible for the member server or standalone or nondomain-joined system to have Administrator rights on the system. prevents CWE-250

References